title: Blood clearance and tissue distribution of PEGylated and non-PEGylated gold nanorods after intravenous administration in rats.
abstract: OBJECTIVE
  To develop and determine the safety of gold nanorods, whose aspect ratios can be tuned to obtain plasmon peaks between 650 and 850 nm, as contrast enhancing agents for diagnostic and therapeutic applications.
  
  
  METHODS
  In this study we compared the blood clearance and tissue distribution of cetyl trimethyl ammonium bromide (CTAB)-capped and polyethylene glycol (PEG)-coated gold nanorods after intravenous injection in the tail vein of rats. The gold content in blood and various organs was measured quantitatively with inductively coupled plasma mass spectrometry.
  
  
  CONCLUSIONS
  The CTAB-capped gold nanorods were almost immediately (< 15 min) cleared from the blood circulation whereas the PEGylation of gold nanorods resulted in a prolonged blood circulation with a half-life time of 19 h and more wide spread tissue distribution. While for the CTAB-capped gold nanorods the tissue distribution was limited to liver, spleen and lung, the PEGylated gold nanorods also distributed to kidney, heart, thymus, brain and testes. PEGylation of the gold nanorods resulted in the spleen being the organ with the highest exposure, whereas for the non-PEGylated CTAB-capped gold nanorods the liver was the organ with the highest exposure, per gram of organ.
  
  
  CONCLUSIONS
  The PEGylation of gold nanorods resulted in a prolongation of the blood clearance and the highest organ exposure in the spleen. In view of the time frame (up to 48 h) of the observed presence in blood circulation, PEGylated gold nanorods can be considered to be promising candidates for therapeutic and diagnostic imaging purposes.
authors.affiliation: Laboratory for Health Protection Research, National Institute for Public Health & the Environment (RIVM), Bilthoven, The Netherlands.
authors.forename: Daniëlle Pk
authors.initials: DP
authors.lastname: Lankveld
authors.forename: Raja G
authors.initials: RG
authors.lastname: Rayavarapu
authors.forename: Petra
authors.initials: P
authors.lastname: Krystek
authors.forename: Agnes G
authors.initials: AG
authors.lastname: Oomen
authors.forename: Hennie W
authors.initials: HW
authors.lastname: Verharen
authors.forename: Ton G
authors.initials: TG
authors.lastname: van Leeuwen
authors.forename: Wim H
authors.initials: WH
authors.lastname: De Jong
authors.forename: Srirang
authors.initials: S
authors.lastname: Manohar
mesh_terms: D000818:Animals; D000077286:Cetrimonium; D002593:Cetrimonium Compounds / Q000737:chemistry / Q000493:pharmacokinetics*; D006046:Gold / Q000737:chemistry / Q000493:pharmacokinetics*; D006207:Half-Life; D008297:Male; D043942:Nanotubes / Q000737:chemistry* / Q000648:ultrastructure; D011092:Polyethylene Glycols / Q000737:chemistry / Q000493:pharmacokinetics*; D051381:Rats; D017208:Rats, Wistar; D014018:Tissue Distribution
chemical_list: D002593:Cetrimonium Compounds; D011092:Polyethylene Glycols; D006046:Gold; D000077286:Cetrimonium